Largest usually classical physics refers to pre-1900 physics while modern physics refers to post-1900 physics which incorporates elements of quantum mechanics and relativity.
😊In the context of quantum mechanics classical theory refers to theories of physics do not use the quantisation paradigm which includes classical mechanics and relativity.
😊Unlike quantum physics classical physics is generally characterized by the principle of complete determinism although deterministic interpretations of quantum mechanics do exist.
😊The correspondence principle says classical accounts are approximations to quantum mechanics are in support of all practical purposes equivalent to quantum mechanics when dealing with macro-scale events.
😊Classical Newtonian physics has formally been replaced by quantum mechanics on the small scale and relativity on the large scale.
😊Likewise classical field theories such as general relativity and classical electromagnetism are those do not use quantum mechanics.
😊Classic physics is considered the limit of quantum mechanics in support of large number of particles.
😊Modern physics includes quantum theory and relativity when applicable.
😊Computer modeling is essential in support of quantum and relativistic physics.
😊This is as it should be in support of special relativity must agree with Newtonian mechanics at low velocities.
Source:
1.Wikipedia Contributors. “Classical Physics.” Wikipedia, Wikimedia Foundation, 16 Oct. 2020, en.wikipedia.org/wiki/Classical_physics. Accessed 30 Oct. 2020.
2.Wikipedia Contributors. “Philosophical Interpretation of Classical Physics.” Wikipedia, Wikimedia Foundation, 7 Mar. 2019, en.wikipedia.org/wiki/Philosophical_interpretation_of_classical_physics. Accessed 30 Oct. 2020.